Aporte original por: TheLastMillennial ,
If this only happened right after you cleared the history, then it’s not the display, you just need to do a RAM reset. (Take out the backup battery and one of the AAA batteries. Hold down ON for 10 seconds, then put the backup battery back in lastly, put the AAA battery back in.) It may also help to reinstall the OS. Since that’s a more complex procedure I’ll refer you to [https://youtu.be/8HlPgS0elRM?t=10m21s|this video] that explains how to do it. If this has been happening over the course of days or weeks then it’s definitely either display issue or a battery issue. You can try just replacing the batteries but it that doesn’t work then Nick’s answer will help you out.